CN-118938243-B - Automatic mobile station changing measurement method based on mobile laser tracker

Abstract

An automatic mobile station-changing measurement method based on a mobile laser tracker includes the steps of establishing a two-dimensional map coordinate system and a global coordinate system through scanning measurement of a mobile measurement system, carrying out three-dimensional measurement on each reflecting column surface in a map, reconstructing two-dimensional equivalent circle centers of the reflecting columns through three-dimensional measurement data, defining the two-dimensional equivalent circle centers as equivalent datum points between the three-dimensional global coordinate system and the two-dimensional map coordinate system, solving a conversion relation between the three-dimensional equivalent circle centers, calculating the conversion relation between a mobile platform coordinate system and the laser tracker coordinate system, planning a moving path of the mobile measurement system between target measurement stations, completing coarse positioning based on radar scanning and fine positioning based on laser measurement after the moving path reaches a designated station, and finally realizing automatic pointing measurement of a to-be-measured point based on fine positioning data and original calibration information. The method solves the problems of low efficiency and low automation degree of the traditional multi-user collaborative station exchange process, and can realize automatic station exchange measurement without manual control.

Inventors

• ZHANG YANG
• WANG JIAWEI
• LU YONGKANG
• SUN SHOUQUAN
• Yan Ruidi
• LIU SIREN
• GUAN XIAO
• LIU WEI

Assignees

• 大连理工大学

Dates

Publication Date

20260505

Application Date

20240829

Claims (1)

1. 1. An automatic mobile station changing measurement method based on a mobile laser tracker is characterized by comprising the following steps: first, two-dimensional map coordinate system construction and control point coordinate global measurement Firstly, drawing a two-dimensional map coordinate system forward by taking an initial position of a vehicle-mounted laser radar as an origin of the two-dimensional map coordinate system, taking a 0-degree scanning direction as an +X direction, and taking anticlockwise relative to an X axis as a corner, scanning surrounding environment reflection columns by the vehicle-mounted laser radar of a mobile platform, and obtaining coordinates of all reflection columns in the two-dimensional map coordinate system : (1) Wherein, the Is the first in the map coordinate system The coordinates of the individual light-reflecting columns, The number of the reflecting columns is the number; then, measuring all control points in a measuring field by using a vehicle-mounted laser tracker, and establishing a global coordinate system, wherein three-dimensional coordinates of all control points in the global coordinate system The method comprises the following steps: (2) Wherein, the Is under the global coordinate system The coordinates of the individual control points are used, The number of control points; Defining the ground normal direction as the Z-axis direction of the laser radar based on the installation relation between the laser radar and the mobile platform, and supplementing the Z-axis value of the laser radar according to the structural size; (3) Wherein, the Respectively a rotation matrix around an X axis, a Y axis and a Z axis, For a three-dimensional set of coordinate points measured by a vehicle-mounted laser tracker, A three-dimensional coordinate point set after rotation; second, calibrating a laser tracker coordinate system and a mobile platform coordinate system based on the equivalent datum point Firstly, measuring and fitting cylindrical axis vectors of each reflecting column by a vehicle-mounted laser tracker, wherein the cylindrical surface equation of each reflecting column is shown in formula (4): (4) Wherein the axis of the cylindrical surface is Radius of the circular section is Any point on the axis of the cylindrical surface is ; Then, measuring a plurality of points on the upper surface of the cylindrical surface and fitting a plane, calculating the intersection point of the plane and the axis of the cylindrical surface, extracting only the horizontal and vertical coordinates of the intersection point and taking the horizontal and vertical coordinates as the two-dimensional equivalent circle centers of the cylindrical surface of the reflecting column, sequentially obtaining the two-dimensional equivalent circle center coordinates of all the reflecting columns, namely equivalent reference points, and obtaining an equivalent reference point sequence set : (5) Wherein, the Is the first Coordinates of the equivalent datum points; Further, a rotation matrix between the two-dimensional map coordinate system and the global coordinate system is solved based on the plurality of groups of equivalent reference points Translation vector The conversion matrix between the current station laser tracker coordinate system and the two-dimensional map coordinate system is shown as the formula (6): (6) Wherein, the And The first coordinate system of the laser tracker and the second coordinate system of the two-dimensional map are respectively Equivalent circle center coordinates of the reflecting columns; finally, according to the pose of the mobile platform in the two-dimensional map coordinate system The conversion relation between the two-dimensional map coordinate system and the current station laser tracker coordinate system is calculated by adopting the method (7), and the coordinates of the mobile platform in the vehicle-mounted laser tracker coordinate system and the pose relation between the mobile platform and the laser tracker are calculated 、 ; (7) Wherein, the Representing the coordinates of the mobile platform in the laser tracker coordinate system, 、 Is a transformation matrix between a laser tracker coordinate system and a two-dimensional map coordinate system, 、 The method is a conversion relation between a mobile platform coordinate system and a two-dimensional map coordinate system; third step, mobile laser tracker station changing path autonomous planning Firstly, reconstructing a complex three-dimensional measurement scene, obtaining a two-dimensional map containing obstacles by two-dimensional projection of the measurement scene, performing binarization and rasterization treatment on the two-dimensional map, and expanding 1 grid outside the boundary of the grid containing the obstacles as a safety area, wherein the size of the grid is equal to the area of a mobile platform; then, carrying out iterative optimization of the nodes of the moving path according to the valuation function to obtain each node of the whole moving path, and further carrying out reverse tracing to obtain the moving path, considering that the measuring site tends to pay more attention to the moving time, and carrying out the method of A The algorithm is improved, the running time is taken as a valuation function, the steering time penalty term is considered, the shortest running time optimization target is constructed, and the valuation function expression is as follows: (8) Wherein, the Is the initial node through the node An estimated time to reach the target node, For initial node to node Is used for the actual time of the (a), Is a node The estimated time of the best path to the target node, In order to estimate the weight of the time, For additional time (steering penalty term); Finally, simplifying all nodes according to the path sequence from the starting point to the end point, namely simplifying a plurality of nodes on the same linear motion path into an end-to-end node; Fourth, global accurate positioning and autonomous searching measurement are performed by a mobile measurement system based on coarse-fine combination After the mobile platform moves to the target measuring station according to the planned path, combining the calibrated information and the positioning information of the mobile platform in the two-dimensional map coordinate system Solving a pose matrix of the current vehicle-mounted laser tracker in a two-dimensional map coordinate system And (3) with : (9) Wherein, the For the conversion relationship between the current mobile platform coordinate system and the two-dimensional map coordinate system, Respectively converting the coordinate system of the laser tracker and the coordinate system of the mobile platform; And calculating a pose matrix of the laser tracker in the global coordinate system by combining a calibration result between the two-dimensional map coordinate system and the global coordinate system: (10) the two-dimensional conversion matrix is up-scaled to a three-dimensional conversion matrix as shown in formula (11): (11) Wherein, the 、 Respectively a three-dimensional rotation matrix and a translation vector, The height of the origin of the coordinate system of the laser tracker and the height of the XOY plane of the global coordinate system; (12) Wherein, the 、 The coordinates of the corresponding measuring points in the current laser tracker coordinate system and the global coordinate system are respectively; based on conversion relation between global coordinate system and vehicle-mounted laser tracker coordinate system 、 Obtaining the pose of the mobile platform in the global coordinate system by adopting matrix multilevel transmission; (13) Wherein, the Representing the coordinates of the mobile platform within the global coordinate system, Representing a pose matrix of the laser tracker under the global coordinate system; Finally, according to the accurate calculation result of the current pose of the laser tracker in the global coordinate system, the automatic searching and measuring of all to-be-measured points are realized by adopting the pointing searching and measuring technology and the vision auxiliary guiding and measuring technology of the laser tracker.

Description

Automatic mobile station changing measurement method based on mobile laser tracker Technical Field The invention belongs to the field of automatic measurement, and relates to an automatic mobile station changing measurement method based on a mobile laser tracker. Background Measurement-driven machining and assembly become a mainstream mode of in-situ manufacturing of aerospace components, and on the premise of guaranteeing measurement accuracy, improvement of measurement efficiency has become one of key means for shortening manufacturing cycle. The multi-station networking measurement of the laser tracker has become the preferred large-scene measurement technology due to the large measurement range in the manufacturing site, serious shielding of the field measurement sight line and the like. At present, the multi-station networking measurement in the manufacturing site mainly relies on manual replacement of the measurement station, the manual dragging of the laser tracker in the process is time-consuming and labor-consuming, and a plurality of people are required to cooperatively and simultaneously carry the laser tracker, drag power supply and communication cables, so that the automation degree of the station switching mode is extremely low, the station switching efficiency is difficult to promote, and the measurement period is greatly prolonged. The high-flexibility mobile platform and the laser tracker are integrated into a mobile laser measurement system, so that a solution way is provided for solving the problem of low-efficiency station-changing measurement. However, to realize full-automatic mobile station-changing measurement, an information island between a scene and a mobile laser tracker must be opened, so that the problems of positioning and path planning of a mobile measurement system in a complex large scene are solved. Therefore, the invention is mainly oriented to the mobile station-changing measurement process, provides the thought of multi-coordinate system calibration, self-positioning in a large scene and complex scene path planning, adopts the thought to control the mobile measurement system to autonomously move to a pre-planned station, replaces the traditional manual station-changing process, avoids power supply and communication cable dragging, reduces the station-changing movement distance through path planning, and finally realizes short-distance, high-efficiency and automatic mobile station-changing measurement. Patent AGV positioning and path planning method and device, patent number CN202410011939.1 discloses a method for planning an AGV driving path based on a multi-sensor data fusion algorithm. Patent No. CN201510082486.2 discloses a technology for determining AGV position information by combining laser radar data with a Markov method. The two methods realize autonomous navigation positioning of the AGV through multi-sensor fusion and data processing, but the patent only relates to navigation positioning of the AGV body, but does not relate to a large-size measurement scene of the mobile laser tracker, and does not relate to multi-coordinate system calibration modeling under the scene and the like. Therefore, the invention provides an automatic mobile station changing measurement method based on a mobile laser tracker, which solves the problems of low manual station changing efficiency and low automation degree during networking measurement of the laser tracker in a large range on a complex site. Disclosure of Invention The invention discloses an automatic mobile station changing measurement method based on a mobile laser tracker, aiming at the problems of low efficiency and low degree of automation of a station changing process depending on multi-person cooperation and manual work in multi-station networking measurement of the laser tracker. Firstly, establishing a two-dimensional map coordinate system through offline scanning measurement of a mobile measurement system, acquiring three-dimensional coordinates of a series of ground control points under a global coordinate system by adopting a laser tracker, then, carrying out three-dimensional measurement on cylindrical surfaces of all light reflecting columns in a map, reconstructing two-dimensional equivalent circle centers of the light reflecting columns by using three-dimensional measurement data, defining the two-dimensional equivalent circle centers as equivalent datum points between the three-dimensional global coordinate system and the two-dimensional map coordinate system, solving a conversion relation between the three-dimensional global coordinate system and the two-dimensional map coordinate system, then, calculating the conversion relation between the mobile platform coordinate system and the laser tracker coordinate system, planning a moving path of the mobile measurement system between target measurement stations by adopting an improved A-x algorithm, sequentially completing coarse positioning based on radar sca